The present invention is directed to novel additive products and to their use in liquid hydrocarbyl fuels and lubricants as a means of cleaning and/or retarding the formation of deleterious deposits on certain moving parts of, for example, internal combustion engines. More particularly, the invention is directed to reaction products in which polyethers are connected to hydroxyalkylated polyamines via diisocyanates and to fuel and lubricant compositions containing same.
With the ever increasing demand for high performance engines to perform over long periods of time, it is necessary that the moving parts of such engines be maintained in as clean a state as possible, both to prolong the life of the engine and to prolong the life of the vehicle which it propels and to reduce down time and repair of said vehicle. Just to merely maintain satisfactory performance, the moving parts of the engine must not be fouled up or dirty.
Additives are an important means of providing this protection for internal combustion and other similar type engines. As is well known, they may give the fuel compositions new properties or they may enhance properties already present. Nevertheless, the art is constantly seeking new materials to enhance the performance capabilities of these engines.
Products containing both polyether (also known as polyoxyalkylene) and polyamine fragments are known as fuel disperants as disclosed in U.S. Pat. Nos. 4,234,321 and 4,261,704.
U.S. Pat. No. 4,234,321 is directed to additive products produced by reacting certain hydrocarbyl(polyoxyalkylene) alcohols with phosgene and certain polyamines to produce hydrocarbyl polyoxyalkylene ureylene carbamates.
U.S. Pat. NO. 4,261,704 is directed to polyoxyalkylene polyamines prepared by first reacting a polyoxyalkylene polyol or a polyoxyalkylene glycol monoether with a halogen-containing compound. The resulting halogenated ether is then aminated by reaction with a mono- or polyamine. The resulting products are substantialy monoamine or polyamine derivatives useful as intermediates for preparing cationic surfactants, cationic polymers and also as fuel detergent additives. The dispersants disclosed by these patents are not made using diiosocyanates which is a critical aspect of the present invention.
U.S. Pat. No. 4,696,755 is directed to lubricating oils containing an additive comprising hydroxy polyether amines. U.S. Pat. No. 4,699,724 is directed to additives prepared by coupling two mono-alkenyl succinimides with an aldehyde and a phenol. The above additives may be prepared in a variety of ways. None of these ways uses diisocyanates, however.
U.S. Pat. No. 3,844,965 discloses diisocyanate bridged polyether-polyamines as lubricant dispersants. This patent mentions C.sub.30 to C.sub.200 hydrocarbyl substituted amines whereas the polyamines in our work are described as C.sub.6 to C.sub.30 hydroxyhydrocarbyl substituted amines and the diisocyanates are attached to the amines through carbamate linkages whereas the '965 patent utilizes urea linkages. Further, no mention is made of fuel applications or compositions.
Polyamine-containing dispersants are therefore well known in the art; however, the modifications described herein are novel and result in products exhibiting excellent multifunctional properties. These products have all of the primary and secondary nitrogens of the polyamine converted into tertiary amines. This improves the oxidative stability of the products. The incorporated polyether provides the solubility needed for good dispersancy. It should also provide better oxidative stability than polyisobutylene-containing dispersants.
It is accordingly, very desirable for lubricant and fuel compositions to have multifunctional, detergent/dispersancy/antioxidant additives which effectively control the buildup of deleterious materials in such intake systems of internal combustion engines as the carburetor, fuel injectors, and valves.